docs(06): create Phase 6 plans for Lab 05 Database & RDS

- 06-PLAN.md: Combined execution plan (test + docs + infra)
- 06-RESEARCH.md: Domain research on PostgreSQL, RDS parallels

Lab 05 integrates all previous concepts:
- Lab 01: Non-root containers (INF-01)
- Lab 02: Private networks (INF-02)
- Lab 03: Resource limits (INF-03)
- Lab 04: Named volumes (INF-04)

Key concepts:
- PostgreSQL in private network → RDS in VPC
- Named volume → EBS volume
- Resource limits → DB instance class

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.planning/phases/06-lab-05-database-rds/06-PLAN.md

@@ -0,0 +1,117 @@
+---
+phase: 06-lab-05-database-rds
+plan: 01
+type: execute
+wave: 0
+depends_on: [02-lab-01-iam-sicurezza, 03-lab-02-network-vpc, 04-lab-03-compute-ec2, 05-lab-04-storage-s3]
+files_modified:
+  - labs/lab-05-database/tests/01-database-creation-test.sh
+  - labs/lab-05-database/tests/02-private-network-test.sh
+  - labs/lab-05-database/tests/03-persistence-test.sh
+  - labs/lab-05-database/tests/04-security-test.sh
+  - labs/lab-05-database/tests/99-final-verification.sh
+  - labs/lab-05-database/tests/run-all-tests.sh
+  - labs/lab-05-database/tests/quick-test.sh
+autonomous: true
+requirements: [LAB-05, TEST-01, TEST-05, INF-01, INF-02, INF-03, INF-04]
+user_setup: []
+
+must_haves:
+  truths:
+    - "Test scripts validate PostgreSQL deployment in private network"
+    - "Tests verify database is NOT accessible from host (INF-02)"
+    - "Tests verify data persistence (INF-04)"
+    - "Tests verify resource limits (INF-03)"
+    - "Tests verify non-root execution (INF-01)"
+  artifacts:
+    - path: "labs/lab-05-database/tests/01-database-creation-test.sh"
+      provides: "Database creation validation"
+      min_lines: 80
+    - path: "labs/lab-05-database/tests/02-private-network-test.sh"
+      provides: "Private network isolation testing"
+      min_lines: 100
+    - path: "labs/lab-05-database/tests/03-persistence-test.sh"
+      provides: "Data persistence verification (INF-04)"
+      min_lines: 80
+    - path: "labs/lab-05-database/tests/04-security-test.sh"
+      provides: "Security compliance testing (INF-01, INF-02, INF-03)"
+      min_lines: 100
+    - path: "labs/lab-05-database/tests/99-final-verification.sh"
+      provides: "Student double-check command"
+      min_lines: 120
+    - path: "labs/lab-05-database/tests/run-all-tests.sh"
+      provides: "Test orchestration with fail-fast"
+      min_lines: 60
+    - path: "labs/lab-05-database/tests/quick-test.sh"
+      provides: "Quick validation for development"
+      min_lines: 40
+key_links:
+  - from: "tests/02-private-network-test.sh"
+    to: "Lab 02 private networks"
+    via: "VPC private network concepts"
+    pattern: "private.*network"
+  - from: "tests/03-persistence-test.sh"
+    to: "Lab 04 named volumes"
+    via: "Volume persistence patterns"
+    pattern: "volume.*persistence"
+---
+
+<objective>
+Create comprehensive test infrastructure for Lab 05 (Database & RDS) following TDD RED phase methodology. Tests validate PostgreSQL deployment in private network, data persistence, resource limits, and full security compliance (INF-01, INF-02, INF-03, INF-04).
+
+Purpose: Establish verification foundation before implementing database infrastructure. Tests fail initially (RED phase) and pass after implementation (GREEN phase in Plan 06-03).
+
+Output: 7 bash test scripts covering database creation, private network isolation, persistence, security compliance, and final verification for students.
+</objective>
+
+<execution_context>
+@/home/luca/.claude/get-shit-done/workflows/execute-plan.md
+@/home/luca/.claude/get-shit-done/templates/summary.md
+</execution_context>
+
+<context>
+@.planning/REQUIREMENTS.md
+@.planning/phases/02-lab-01-iam-sicurezza/02-01-SUMMARY.md
+@.planning/phases/03-lab-02-network-vpc/03-01-SUMMARY.md
+
+# Integration with Previous Labs
+
+Lab 05 integrates concepts from all previous labs:
+- **Lab 01:** Non-root containers (INF-01)
+- **Lab 02:** Private networks (INF-02)
+- **Lab 03:** Resource limits (INF-03)
+- **Lab 04:** Named volumes (INF-04)
+
+# Test Requirements
+
+1. **Database Creation (01-database-creation-test.sh)**
+   - Verify PostgreSQL container starts
+   - Verify database initialization
+   - Verify connection parameters
+
+2. **Private Network Isolation (02-private-network-test.sh)**
+   - Verify database is in private network
+   - Verify database NOT accessible from host
+   - Verify only containers in same network can connect
+
+3. **Data Persistence (03-persistence-test.sh)**
+   - Verify data survives container restart
+   - Verify data survives container removal
+   - Verify volume is correctly mounted
+
+4. **Security Compliance (04-security-test.sh)**
+   - INF-01: Container runs as non-root
+   - INF-02: No ports exposed on host
+   - INF-03: Resource limits configured
+   - INF-04: Named volume for data
+
+5. **Final Verification (99-final-verification.sh)**
+   - End-to-end student validation
+   - All INF requirements verified
+   - Database functionality tested
+
+# Tone Guidelines
+- Direct, simple language (Italian)
+- No emojis
+- Technically accurate
+- Step-by-step with verification at each step